Renewable fuse



F. G. VON HOORN RENEWABLE FUSE Filed Aug. 27; 1947 \nventor: Fred 6. Von Hoorn, b W W H I His Attorney.

Patented Sept. 21, 1948 RENEWABLE FUSE Fred G. von Hoorn, Nichols, Conn, assignor to General Electric Company, a corporation of New York Application August 27, 1947, Serial No. 770,823 1 Claim. (c1. zoo-4.31)

The present invention relates to electric fuses and more particularly to renewable enclosed cartridge fuses.

It is an object of the present invention to provide an improved renewable fuse having a minimum number of loose parts and in which the interior of the fuse cartridge is completely accessible for the ready removal of blown link sections. A still further object is to provide a conveniently renewable fuse which is inexpensive to manufacture.

Other objects of the invention as well as novel features of construction will be apparent from the following description taken in connection with the accompanying drawing in which Fig. l is an elevation of my fuse partly in longitudinal section; Fig. 2 is a section taken along the line 2-2 in Fig. 1; Fig. 3 is an elevation of one end of my fuse in a stage of manufacture; Fig. 4 is a section taken along the line 4--4 in Fig. 3; and Fig, 5 is an exploded perspective view of one end of my fuse cartridge.

My improved fuse comprises a fuse link containing cartridge having a tubular casing I of suitable insulating material. The ends of the casing I are reduced in diameter and exteriorly threaded as at 2 and 3. Engaging the threads 2 at the upper end of the fuse as viewed in Fig. 1 is a metal bushing 4 which is secured to the casing I in any suitable manner, as for example, by the pin 5. The bushing 4 is cup-shaped, thereby closing the end of the casing except for a slot 6 adapted to receive the end of a fuse link I in such a manner that the end of the link 8 may be bent over against the outside end of the cup-shaped bushing 4. The outside of the bushing I is threaded as indicated at 9 to receive a threaded cap II]. The inside end of the cap I is provided with a boss I I adapted when the cap is screwed into place to press against and make firm electrical contact with the end 8 of the fuse link I.

At the opposite end of the casing I the threads 3 are engaged by a metallic, interiorly threaded bushing I2, which is secured to the casing in any suitable manner, as by means of a, pin I3. The bushing I2 is made from a simple cylinder preferably having an internal diameter greater than the internal diameter of the casing. This bushing is exteriorly threaded at I4 to receive an interiorly threaded end cap I which is in all respects similar to and interchangeable with the cap ID at the other end of the fuse. Below the threads I4 the cylindrical bushing is made of reduced cross section as indicated at It. Along the bottom edge of the bushing I2 there is hinged a fuse link supporting member I'I over which the end I8 of the fuse link I can be bent. When a new link is installed in the fuse, the end I8 of fuse link I is held in placeby the boss I9 of the cap I5.

An important feature of my invention resides in the manner of construction and attachment of the hinged member I'I. As illustrated in Fig. 3, the initially cylindrical bushing I2 with its reduced diameter end portion It has cut into its edge a T-shaped slot Zil. The opposed projections formed by the metal adjacent the slot, that is the projections 2| and 22, are then bent inward and flattened, thereby forming a hinge pin for the member H, as shown in Figs. 4 and 5. The hinged member or door I! is formed from sheet metal and is shaped substantially as shown in Figs. 2 and 5. It is large enough to cover somewhat more than one-half of the end of the bushing I2. One of its edges 23 is straight so that the end I8 of the fuse link can be bent over against it. The other edges of the member I! are shaped to conform to the perimeter of the bushing end IS. The edge opposite the edge 23 is, however, formed with a tang 24, which is bent, initially as shown in Fig. 5 and finally substantially completely closed as shown in Fig. 1, to form the eye of the hinge and is adapted to engage the hinge pin formed by the bent projections 2| and 22 of the bushing.

The inner surface of the member I1 is provided with upwardly extending projections or bosses 25 and 26 which are located so as to fall just insid the end I6 of the bushing I2, thereby serving to locate the member II properly when the fuse is assembled and permitting a loose fit in the hinge.

In the assembly of my fuse the cup-shaped bushing 4 is first tightly screwed to the casing I and fixed to it as by the pin 5. The bushing I2 in its initial cylindrical form is then tightly screwed to the other end of the casing and fixed to it as by the pin I3. Thereafter, the slot 20 is pierced in the edge of bushing I2 and located so as to be on the same side of the casing as the slot 6 in the end of bushing I. Subsequently, the projections 2| and 22 are bent inward and flattened, forming a hinge pin which is engaged by the hooked tang 24 of the member I'I. Finally, the end of tang 24 is closed down, thereby forming a complete hinge and securely hinging the member I1 on the end I6 of the bushing I2. The fuse link I can then be inserted in the casing, its end 8 projecting through the slot 6 and being bent over the end of the bushing 4 as shown in Fig. 1. The other end I8 of the fuse link I is then bent over 3 the hinge member or door l1, and finally both end caps l and 15 are screwed into place.

In replacing a blown fuse link, the end caps Ill and I5 are removed, if necessary with the aid of the screw driver slots 21, and the hinged door member I 1' opened, whereupon the blown fuse link sections will readily fall out of the casing. The door I! is then closed and a new fuse link inserted, as described above.

It will be evident to those skilled in the art that my improved hinged closure plate construction may, if desired, be used at both ends of the fuse.

It will be observed that with my improved construotion there are no loose parts in my fuse which may readily become lost, or which may inadvertently be omitted in reassembling the fuse. Moreover, full access to the interior of the fuse casing is provided by the door H; the latter, .because of the construction and positioning of its hinge outside of the internal boundary (prolonged) of the casing, does not in any way provide any obstruction in the interior of the fuse on which blown fuse link portions may catch. Moreover, the hinge, being positioned on the perimeter of the bushing, will not be subjected to the full force of a blowing fuse link, and thereby will not be likely to become badly fouled. This location of the hinge also permits the hinged member to swing opennearly a full 180 degrees. It will further be noted that my fuse construction is substantially completely gas tight-and will pass the severe requirements of the underwriters. Finally, it will also be evident that my fuse parts can be made with simple tools and can, therefore, be produced at a low cost.

What I claim as new and desire to secure by Letters Patent in the United States is:

In a refillable fuse member having an insulating casing, a metallic open ended bushing at one end of the casing, a cover plate partly closing the open end of the bushing and adapted to have one end of a fuse link bent to lie along the outer surface of said plate and an end cap detachably secured to said bushing and adapted when tight to clamp the fuse link against said plate; the combination therewith of a hinge for said cover plate comprising a tang extending from one edge of said plate, said tang being bent toward the inner surface of the plate into an eye adapted to engage a hinge pin, the end of said bushing having a T- slot in its periphery with the stem of the T extending to the end of the bushing forming opposed tongues, said tongues being bent inwards and flat toned and being thereby adapted together to form a hinge pin at the end of the bushing for receiving said eye.

FRED G. VON HOORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,773,183 Hickey Aug. 19, 1930 1,874,948 Fogal Aug. 30, 1932 1,907,740 Clark Ma 9, 1933 1,953,011 Cote Mar. 27, 1934 

